Air handling unit

ABSTRACT

An air handling unit having multiple fans includes a damper assembly to limit recirculation of air past a non-operating fan. The damper assembly includes a panel adjustably positioned between two channels to allow the discharge of the multiple fans to be substantially opened or to be substantially closed.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority from and the benefit of U.S. Provisional Application No. 61/016,834, entitled ISOLATION DAMPER FOR AIR HANDLING UNIT, filed Dec. 27, 2007, which is hereby incorporated by reference.

BACKGROUND

The application relates generally to an air handling unit. The application relates more specifically to the operation of an air handling unit having an isolation damper.

Air handling units (AHUs) are one of several components in heating, ventilation, and air conditioning systems (HVAC systems). The AHU can house a number of components used to circulate air for climate control in a structure. AHU components can include motors, heat exchangers, and blowers or fans.

The AHU is an enclosed interconnected framed panel structure. The framed panel structures can have insulated panels that are supported between framing members, also referred to as raceways, to define interconnected rectangular compartments. AHU constructions can include a pair of fans generally positioned side-by-side to one another to circulate air for climate control. Each fan can be capable of satisfying the air flow requirements of the HVAC system. Stated another way, if one fan becomes inoperable, the remaining fan can continue to provide uninterrupted capacity operation in the HVAC system. However, with the side-by-side fan arrangement, an amount of air from the operating fan is recirculated through the fan opening of the non-operational fan, thereby degrading performance of the system.

AHUs can also incorporate a damping arrangement, in which a plate disposed in the air stream of the supply air region of the AHU fans and is rotatable between an open position and a closed position. Such damping arrangements increase the size of the AHU, possibly rendering certain AHU constructions unusable, due to space constraints.

SUMMARY

The present invention relates to an damper assembly for an air handling unit including a frame adapted to be mounted in an opening in the air handling unit; at least one panel, the at least one panel being configured to be moveable within the frame; and the at least one panel is positionable between a first position and a second position in the frame, the first position of the at least one panel corresponding to a position to substantially obstruct a portion of the opening associated with a fan of the air handling unit and the second position of the at least one panel corresponding to a position to enable unobstructed access to the portion of the opening associated with the fan of the air handling unit.

The present invention also relates to a damper assembly for an air handling unit including a frame adapted to be mounted in an opening in the air handling unit; at least one closure member, the at least one closure member being configured to be selectively retracted and expanded; and the at least one closure member is positionable between a first position and a second position in the frame, the first position of the at least one closure member corresponding to a position to substantially obstruct a portion of the opening associated with a fan of the air handling unit and the second position of the at least one closure member corresponding to a position to enable unobstructed access to the portion of the opening associated with the fan of the air handling unit.

The present invention also relates to an air handling unit including a housing, the housing including a plurality of openings to enable flow of air through the housing, a pair of fans positioned in the housing, at least one wall, the at least one wall being configured and positioned in the housing to separate the pair of fans and to define an individual discharge opening and inlet for each fan of the pair of fans, a damper assembly including a frame mounted in an opening of the plurality of openings, at least one panel, the at least one panel being configured to be moveable within the frame, and the at least one panel is positionable between a first position and a second position in the frame, the first position of the at least one panel being configured to substantially obstruct a discharge opening of a fan of the pair of fans and the second position of the at least one panel being configured to enable unobstructed access to the discharge opening of the fan of the pair of fans.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows an exemplary embodiment of an HVAC system in a commercial environment.

FIG. 2 shows schematically an exemplary embodiment of an HVAC system.

FIG. 3 shows a perspective view of an exemplary embodiment of an AHU.

FIG. 4 shows a perspective view of an exemplary embodiment of a damper assembly for an AHU.

FIG. 5 shows a perspective view the damper assembly of FIG. 4 in alternate configuration.

FIG. 6 shows a cross sectional view of the panels of the damper assembly along line 66 in FIG. 4.

FIG. 7 shows a cross sectional view of the panels of the damper assembly along line 7-7 in FIG. 5.

FIG. 8 shows a partial cross sectional view of the damper assembly along line 8-8 in FIG. 9.

FIG. 9 shows a perspective view of the damper assembly of FIG. 4 in another alternate configuration.

FIG. 10 shows a perspective view of another exemplary embodiment of a damper assembly for an AHU.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring to FIG. 1, an exemplary environment for an HVAC system 31 in a building or structure 13 for a commercial setting is shown. System 31 may include vapor compression system 210 (see FIG. 2) incorporated into a rooftop unit 15 that can supply a chilled liquid that may be used to cool building 13. System 31 can also include a boiler system 305 to supply a heated liquid that may be used to heat building 13, and an AHU 10 that circulates air through building 13. AHU 10 can be connected to vapor compression system 210 and boiler system 305 by conduits 27. AHU 10 can include an air return duct 29 and an air supply duct 25. System 31 is shown with a separate AHU 10 on each floor of building 13, but it is to be understood that the components may be shared between or among floors.

Referring to FIGS. 2 and 3, vapor compression system 210 can include an AC power source 220 that supplies a variable speed drive (VSD) 230 incorporated in a power/control panel 235. AC power source 220 provides single phase or multi-phase (for example, three phase), fixed voltage, and fixed frequency AC power to VSD 230 from an AC power grid or distribution system that is present at a site. In an exemplary embodiment, VSD 230 can be enclosed in a separate housing from power/control panel 235. VSD 230 powers a motor 240 that drives a compressor 260, as controlled by power/control panel 235. Compressor 260 compresses a refrigerant vapor and delivers the vapor to a condenser 270 through a discharge line 272. Compressor 260 may be a centrifugal compressor, reciprocating compressor, screw compressor, scroll compressor, or other suitable type of compressor. The refrigerant vapor delivered by compressor 260 to condenser 270 enters into a heat exchange relationship with a fluid, for example water, flowing through a tube bundle(s) 255 connected to a cooling tower 250. However, in an exemplary embodiment, condenser 270 may use air as the heat exchange fluid. The refrigerant vapor in condenser 270 undergoes a phase change to a refrigerant liquid as a result of the heat exchange relationship with the heat exchanger fluid. The liquid refrigerant from condenser 270 flows through an expansion device 275 before entering evaporator 280.

Evaporator 280 can include tube bundle(s) 285 having a supply line 285S and a return line 285R connected to a heat exchanger located in AHU 10. Water or any other suitable secondary liquid, for example, ethylene, ethylene glycol, or calcium chloride brine, can travel into evaporator 280 via return line 285R and exit evaporator 280 via supply line 285S. The liquid refrigerant in evaporator 280 enters into a heat exchange relationship with the water in tube bundle(s) 285 to lower the temperature of the secondary liquid in tube bundle(s) 285. The refrigerant liquid in evaporator 280 undergoes a phase change to a refrigerant vapor as a result of the heat exchange relationship with the liquid in tube bundle(s) 285. The vapor refrigerant in the evaporator 280 can then return to compressor 260 to complete the cycle.

Boiler system 305 can include tube bundle(s) 295 having supply line 295S and return line 295R connected to a heat exchanger 300 in AHU 10. Water or any other suitable secondary liquid travels into boiler system 305 via return line 295R and exits boiler system 305 via supply line 295S. In an exemplary embodiment, heat exchanger 290 and heat exchanger 300 can be a single heat exchanger.

Referring to FIGS. 4, 5, and 9, heat exchanger 290 and/or heat exchanger 300 can be incorporated into AHU 10. AHU 10 can include a frame 14, such as a rectangular frame, and including one end 12 configured to be coupled with ducting (not shown) for circulating air from AHU 10 to a structure for regulating the temperature of the structure. Alternatively, end 12 can be coupled with ducting for receiving air into AHU 10 from the structure and/or the outside. In an exemplary embodiment, AHU 10 may include a housing comprising a plurality of openings to enable flow through the housing. In another exemplary embodiment, the housing is defined by a top wall, a bottom wall, and two side walls interposed between the top wall and the bottom wall. In the embodiment, the top wall, the bottom wall, and the two side walls form the frame defining the opening, and enclosing a plurality of fans.

As shown, end 12 of the AHU 10 can include an isolation damper assembly including a pair of opposed struts or posts 16 disposed in close proximity to the vertical corners of AHU 10. Two pairs of struts 18 (one pair shown in FIG. 5 and the other pair shown in FIG. 9) are disposed along end 12 substantially parallel with posts 16. Struts 18 separate an upper channel 26 from a lower channel 28, each channel 26, 28 being substantially horizontally positioned. As shown in FIG. 5, one pair of struts 18, upper channel 26 and lower channel 28 define an opening 32 formed in the isolation damper assembly through which air from a first fan (disposed within AHU 10 and not shown) flows to regulate the temperature of a structure. Similarly, as shown in FIG. 9, the other pair of struts 18, upper channel 26 and lower channel 28 define an opening 30 formed in the isolation damper assembly through which air from a second fan (disposed within AHU 10 and not shown) flows to regulate the temperature of the structure.

Referring to FIG. 5, a post 34 can be along the central portion of end 12 between the pairs of struts 18. Post 34 divides end 12 into two portions. To each side of post 34, a panel 36 is positioned between post 34 and strut 18 to provide a generally fluid tight region along end 12 between the pairs of struts 18. Similarly, as shown in FIG. 4, a panel 38 is disposed on each side of end 12 between post 16 and strut 18 to provide a generally fluid tight region between post 16 and strut 18. Additionally, panels 20 are positioned between upper channel 26 and an upper surface 44 of AHU 10, to provide a generally fluid tight region between upper channel 26 and upper surface 44.

As shown in FIGS. 4, 5, and 9, a first moveable panel 22 and second moveable panel 24 may be adjustably positioned between upper channel 26 and lower channels 28. The upper and/or lower portions of moveable panels 22, 24 may include a movement mechanism that is received in upper and/or lower channels 26, 28 permitting moveable panels 22, 24 to be positioned along the damper assembly. In an exemplary embodiment, the movement mechanism may be a sliding movement mechanism, for example, a low friction edge of moveable panels 22, 24. In another exemplary embodiment, the movement mechanism may be a set of wheels (not shown). Pins (not shown) or other devices may be used to secure the positions of moveable panels 22, 24 with respect to openings 30, 32. FIG. 4 shows moveable panels 22, 24 in overlapping relationship and overlying panels 36, so that openings 30, 32 are generally unobstructed by moveable panels 22, 24. In this position, the first and second fans (not shown) corresponding to openings 30, 32 may both be operating.

In FIG. 5, moveable panels 22, 24 are positioned to generally obstruct opening 30 and only the fan corresponding to opening 32 would be operated. Moveable panels 22, 24 generally eliminate recirculation of air through opening 30. Similarly, as shown in FIG. 9, moveable panels 22, 24 may be positioned to substantially obstruct opening 32 and only the fan corresponding to opening 30 would be operated. Moveable panels 22, 24 generally eliminate recirculation of air through opening 32.

End 12, including moveable panels 22, 24, panels 20, 36, 38, struts 18, and posts 16, 34, may be configured in an extremely compact AHU end construction. The compact AHU end construction can decrease space allocated for the AHU. Such compact AHU end constructions, which may reduce the thickness of end 12, as compared to conventional rotating valve arrangements, such as flapper valves, permits the use of AHUs having multiple fans with increased operational capacities. Furthermore, repair to the AHU may be conducted without resulting in impairment of the circulation of the air by increasing the capacity for one fan to handle the decrease in capacity associated with repair of another fan.

In other exemplary embodiments, the AHU and isolation damper assembly may be configured with more than two moveable panels 22, 24, and may also be configured with more than two fans and corresponding openings. The two or more fans may be arranged in any configuration including vertically stacked. Moveable panels 22, 24 may be configured for manual or automated operation, such as by a belt or actuator (not shown).

In another exemplary embodiment, moveable panels 22, 24 may be configured to partially or totally overlap each other when positioned over panels 36. To enable moveable panels 22, 24 to be overlapped more easily, a portion 23 of one of moveable panels 22, 24 can be offset to clear any corresponding protrusion of the other moveable panel. FIGS. 4 and 6 show moveable panel 22 with offset portion 23 overlapping moveable panel 24.

As shown in FIGS. 5 and 9, the combined width of struts 18, panels 36 and post 34 is less than the width of openings 30, 32. When moveable panels 22, 24 slightly overlap, as shown in FIG. 7, moveable panels 22, 24 can obstruct one of openings 30, 32, as shown in FIGS. 5 and 9. By overlapping moveable panels 22, 24, and positioning them over panels 26, as shown in FIG. 6, openings 30, 32 are substantially unobstructed by moveable panels 22, 24, as shown in FIG. 4.

To enable moveable panels 22, 24 to be more easily positioned, a tab 25 can be formed on an edge of each of moveable panels 22, 24 opposite portion 23, as shown in FIGS. 6 and 7. Tab 25 can protrude generally perpendicularly from moveable panels 22, 24.

As shown in FIG. 8, each channel 26, 28 has a vertical first leg 1 with two horizontal legs 3, 5 (with second leg 3 being shorter than third leg 5) extending substantially perpendicularly from opposite ends of the vertical first leg 1 in the same direction. Second leg 3 has a fourth leg 7 extending from the end opposite to first leg 1 toward third leg 5 and substantially parallel to first leg 1. Third leg 5 has a fifth leg 9 extending from the end opposite to first leg 1 toward second leg 3 and substantially parallel to first leg 1.

FIG. 10 shows an AHU 110 with struts 118 configured to receive a flexible rectangular closure member 112 that can be rolled and unrolled about an axis parallel to one edge of flexible closure member 112. In an exemplary embodiment, closure members 112 may be selectively retracted and expanded. The cross section of struts 118 are generally C-shaped. When flexible closure member 112 is unrolled, the edge of flexible closure member 112 is between the two parallel legs of the “C” and near the leg that is interposed between to the two parallel legs.

Flexible closure member 112 may be formed of stiffer elongated segments or pieces that are connected by more flexible and narrower segments or pieces. For flexible closure member 112 to close opening 30, the free end of flexible closure member 112 may be unrolled in direction 40 to engage corresponding struts 118 until opening 30 is generally closed by flexible closure member 112. Similarly, for flexible closure member 112 to close opening 32, the free end of flexible closure member 112 may be unrolled in direction 42 to engage corresponding struts 118 until opening 32 is generally close by flexible closure member 112.

In other exemplary embodiments, flexible closure member 112 may be configured to be rolled/unrolled from above or below openings 30, 32, and may be positioned above upper surface 44 or beneath the lower surface of AHU 110. Flexible closure member 112 may be configured to be rolled/unrolled from either of vertically disposed sides 126, 128 of openings 30, 32. Alternately, the location of the rolled of flexible closure member 112 may be positioned between the AHU fans or positioned between the fan and an exterior wall of the AHU.

While only certain features and embodiments of the invention have been shown and described, many modifications and changes may occur to those skilled in the art (for example, variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (for example, temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the claimed invention). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation. 

1. A damper assembly for an air handling unit comprising: a frame adapted to be mounted in an opening in the air handling unit; at least one panel, the at least one panel being configured to be moveable within the frame; and the at least one panel is positionable between a first position and a second position in the frame, the first position of the at least one panel corresponding to a position to substantially obstruct a portion of the opening associated with a fan of the air handling unit and the second position of the at least one panel corresponding to a position to enable unobstructed access to the portion of the opening associated with the fan of the air handling unit.
 2. The damper assembly of claim 1, wherein the at least one panel comprises a pair of panels, the pair of panels being configured to be positionable in the frame in an overlapping position.
 3. The damper assembly of claim 3, wherein each panel of the pair of panels comprises a tab, the tab being configured and positioned to assist with movement of the panel in the frame.
 4. The damper assembly of claim 4, wherein one of the panels of the pair of panels comprises a protruding portion, the protruding portion being configured and positioned to overlap the tab of the other panel of the pair of panels.
 5. The damper assembly of claim 1, wherein the frame comprises a plurality of struts.
 6. The damper assembly of claim 5, wherein the frame further comprises two channels separated by the plurality of struts.
 7. The damper assembly of claim 1, further comprising a device to secure the at least one panel in the frame, the device being configured to substantially prevent movement of the at least one panel.
 8. A damper assembly for an air handling unit comprising: a frame adapted to be mounted in an opening in the air handling unit; at least one closure member, the at least one closure member being configured to be selectively retracted and expanded; and the at least one closure member is positionable between a first position and a second position in the frame, the first position of the at least one closure member corresponding to a position to substantially obstruct a portion of the opening associated with a fan of the air handling unit and the second position of the at least one closure member corresponding to a position to enable unobstructed access to the portion of the opening associated with the fan of the air handling unit.
 9. The damper assembly of claim 8, wherein the at least one closure member comprises interconnected elongated segments.
 10. The damper assembly of claim 8, wherein the at least one closure member constitutes two closure members configured and positioned to obstruct or enable unobstructed access to the opening and portions of the opening.
 11. The damper assembly of claim 8, wherein the closure member is further configured to be rolled into a cylinder.
 12. An air handling unit comprising: a housing, the housing comprising a plurality of openings to enable flow of air through the housing; a pair of fans positioned in the housing, at least one wall, the at least one wall being configured and positioned in the housing to separate the pair of fans and to define an individual discharge opening and inlet for each fan of the pair of fans; a damper assembly comprising: a frame mounted in an opening of the plurality of openings; at least one panel, the at least one panel being configured to be moveable within the frame; and the at least one panel is positionable between a first position and a second position in the frame, the first position of the at least one panel being configured to substantially obstruct a discharge opening of a fan of the pair of fans and the second position of the at least one panel being configured to enable unobstructed access to the discharge opening of the fan of the pair of fans.
 13. The air handling unit of claim 12, wherein a width of the at least one panel is less than or equal to a distance between the discharge openings for the pair of fans.
 14. The air handling unit of claim 12, wherein the at least one panel comprises a pair of panels.
 15. The air handling unit of claim 12, wherein the damper assembly comprises a member positioned in the frame between the discharge openings for the pair of fans.
 16. The air handling unit of claim 14, wherein each panel of the pair of panels comprises a tab, the tab being configured and positioned to assist with movement of the panel in the frame.
 17. The air handling unit of claim 16, wherein one panel of the pair of panels comprises a protruding portion, the protruding portion being configured and positioned to overlap the tab of the other panel of the pair of panels.
 18. The air handling unit of claim 12, wherein the frame comprises a plurality of struts and two channels separated by the plurality of struts.
 19. The air handling unit of claim 18, wherein the frame further comprises a plurality of posts connected to the housing.
 20. The air handling unit of claim 12, wherein the damper assembly further comprises a member configured and positioned to obstruct a portion of the opening near the discharge openings for the pair of fans. 